Methods of safely expanding prosthetic heart valves

ABSTRACT

Methods of quickly and easily implanting a quick-connect heart valve prosthesis during a surgical procedure are provided. The heart valve may include a substantially non-expandable, non-compressible prosthetic valve and a plastically-expandable frame, thereby enabling attachment to the annulus without sutures. A system and method for deployment includes an integrated handle shaft and balloon catheter. A safety member disposed between the balloon catheter and handle shaft prevents premature catheter advancement prior to heart valve placement at the annulus, and also may prevent premature balloon inflation prior to full catheter advancement.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/368,335, filed Dec. 2, 2016, now U.S. Pat. No. 10,548,728, which is acontinuation of U.S. patent application Ser. No. 14/847,190, filed Sep.8, 2015, now U.S. Pat. No. 9,968,450, which is a divisional of U.S.patent application No. 13/797,572, filed Mar. 12, 2013, now U.S. Pat.No. 9,125,741, which is a continuation-in-part of U.S. patentapplication Ser. No. 13/167,639, filed Jun. 23, 2011, now U.S. Pat. No.8,641,757, which claims the benefit of U.S. Patent Application Ser. No.61/381,931 filed Sep. 10, 2010, the contents all of which areincorporated by reference for all purposes.

FIELD OF THE INVENTION

The present invention generally relates to prosthetic valves forimplantation in body channels. More particularly, the present inventionrelates to unitary surgical prosthetic heart valves configured to besurgically implanted in less time than current valves, and associatedvalve delivery methods.

BACKGROUND OF THE INVENTION

In vertebrate animals, the heart is a hollow muscular organ having fourpumping chambers—the left and right atria and the left and rightventricles, each provided with its own one-way valve. The natural heartvalves are identified as the aortic, mitral (or bicuspid), tricuspid andpulmonary, and are each mounted in an annulus comprising dense fibrousrings attached either directly or indirectly to the atrial andventricular muscle fibers. Each annulus defines a flow orifice.

The atria are the blood-receiving chambers, which pump blood into theventricles. The ventricles are the blood-discharging chambers. A wallcomposed of fibrous and muscular parts, called the interatrial septumseparates the right and left atria. The fibrous interatrial septum is amaterially stronger tissue structure compared to the more friable muscletissue of the heart. An anatomic landmark on the interatrial septum isan oval, thumbprint sized depression called the oval fossa, or fossaovalis.

The synchronous pumping actions of the left and right sides of the heartconstitute the cardiac cycle. The cycle begins with a period ofventricular relaxation, called ventricular diastole. The cycle ends witha period of ventricular contraction, called ventricular systole. Thefour valves ensure that blood does not flow in the wrong directionduring the cardiac cycle; that is, to ensure that the blood does notback flow from the ventricles into the corresponding atria, or back flowfrom the arteries into the corresponding ventricles. The mitral valve isbetween the left atrium and the left ventricle, the tricuspid valvebetween the right atrium and the right ventricle, the pulmonary valve isat the opening of the pulmonary artery, and the aortic valve is at theopening of the aorta.

The anterior portion of the mitral valve annulus abuts the non-coronaryleaflet of the aortic valve. The mitral valve annulus is in the vicinityof the circumflex branch of the left coronary artery, and the posteriorside is near the coronary sinus and its tributaries.

Various surgical techniques may be used to repair a diseased or damagedvalve. In a valve replacement operation, the damaged leaflets areexcised and the annulus sculpted to receive a replacement valve. Due toaortic stenosis and other heart valve diseases, thousands of patientsundergo surgery each year wherein the defective native heart valve isreplaced by a prosthetic valve, either bioprosthetic or mechanical.Another less drastic method for treating defective valves is throughrepair or reconstruction, which is typically used on minimally calcifiedvalves. The problem with surgical therapy is the significant insult itimposes on these chronically ill patients with high morbidity andmortality rates associated with surgical repair.

When the valve is replaced, surgical implantation of the prostheticvalve typically requires an open-chest surgery during which the heart isstopped and patient placed on cardiopulmonary bypass (a so-called“heart-lung machine”). In one common surgical procedure, the diseasednative valve leaflets are excised and a prosthetic valve is sutured tothe surrounding tissue at the valve annulus. Because of the traumaassociated with the procedure and the attendant duration ofextracorporeal blood circulation, some patients do not survive thesurgical procedure or die shortly thereafter. It is well known that therisk to the patient increases with the amount of time required onextracorporeal circulation. Due to these risks, a substantial number ofpatients with defective valves are deemed inoperable because theircondition is too frail to withstand the procedure. By some estimates,about 30 to 50% of the subjects suffering from aortic stenosis who areolder than 80 years cannot be operated on for aortic valve replacement.

Because of the drawbacks associated with conventional open-heartsurgery, percutaneous and minimally-invasive surgical approaches aregarnering intense attention. In one technique, a prosthetic valve isconfigured to be implanted in a much less invasive procedure by way ofcatheterization. For instance, U.S. Pat. No. 5,411,552 to Andersen etal. describes a collapsible valve percutaneously introduced in acompressed state through a catheter and expanded in the desired positionby balloon inflation. Although these remote implantation techniques haveshown great promise for treating certain patients, replacing a valve viasurgical intervention is still the preferred treatment procedure. Onehurdle to the acceptance of remote implantation is resistance fromdoctors who are understandably anxious about converting from aneffective, if imperfect, regimen to a novel approach that promises greatoutcomes but is relatively foreign. In conjunction with theunderstandable caution exercised by surgeons in switching to newtechniques of heart valve replacement, regulatory bodies around theworld are moving slowly as well. Numerous successful clinical trials andfollow-up studies are in process, but much more experience with thesenew technologies will be required before they are completely accepted.

Accordingly, there is a need for an improved device and associatedmethod of use wherein a prosthetic valve can be surgically implanted ina body channel in a more efficient procedure that reduces the timerequired on extracorporeal circulation. It is desirable that such adevice and method be capable of helping patients with defective valvesthat are deemed inoperable because their condition is too frail towithstand a lengthy conventional surgical procedure.

Furthermore, surgeons relate that one of the most difficult tasks whenattempting minimally invasive heart valve implantation or implantationthrough a small incision is tying the suture knots that hold the valvein position. A typical aortic valve implant utilizes 12-24 sutures(commonly 15) distributed evenly around and manually tied on one side ofthe sewing ring. The knots directly behind the commissure posts of aprosthetic aortic valve are particularly challenging because of spaceconstraints. Eliminating the need to tie suture knots or even reducingthe number of knots to those that are more accessible would greatlyfacilitate the use of smaller incisions that reduces infection risk,reduces the need for blood transfusions and allows more rapid recoverycompared to patients whose valves are implanted through the fullsternotomy commonly used for heart valve implantation.

The present invention addresses these needs and others.

SUMMARY OF THE INVENTION

Various embodiments of the present application provide prosthetic valvesand methods of use for replacing a defective native valve in a humanheart. Certain embodiments are particularly well adapted for use in asurgical procedure for quickly and easily replacing a heart valve whileminimizing time using extracorporeal circulation (i.e., bypass pump).

In one embodiment, a method for treating a native aortic valve in ahuman heart to replace the function of the aortic valve, comprises: 1)accessing a native valve through an opening in a chest; 2) placingguiding sutures in the annulus 3) advancing a heart valve within a lumenof the annulus; and 4) plastically expanding a metallic anchoring skirton the heart valve to mechanically couple to the annulus in a quick andefficient manner.

The present application contemplates various means for physicallypreventing movement of the balloon catheter, preferably coupled with avisual reminder not to deploy the catheter prematurely. Furthermore,exemplary heart valve delivery systems also preferably have devices thatprevent premature inflation of a dilatation balloon until the ballooncatheter has been properly advanced.

The exemplary heart valves are a hybrid valve that includes a prostheticvalve having an inner frame assembly defining a non-expandable,non-collapsible orifice, and an expandable frame extending from aninflow end thereof, the expandable frame having a contracted state fordelivery to an implant position and an expanded state;

For example, one system for delivering the exemplary hybrid prostheticheart valve comprises a valve holder attached to the heart valve andhaving a bore, and an elongated handle shaft attached to a proximal endof the valve holder and having a lumen, a proximal end of the handleshaft having a handpiece. An expansion catheter extends through thehandle shaft, has an expandable member on a distal end sized to passthrough the bore of the valve holder, and a proximal end projectingproximally from out of the handpiece. The expansion catheter movesaxially relative to the handle shaft between a retracted position and anadvanced position in which the expandable member is located within theexpandable frame of the heart valve. Finally, the system includes asafety member engaged between the expansion catheter and the handleshaft that prevents distal movement of the expansion catheter from itsretracted position.

In one form, the expansion catheter is a balloon catheter with a luerconnector, and the safety member comprises a locking clip that snapsonto the handpiece and proximal end of the expansion catheter andprevents relative balloon catheter handpiece movement prior to removal.The expansion catheter may be a balloon catheter and the expandablemember is a balloon wherein a proximal end of the balloon catheter has aluer connector, wherein the locking clip covers the luer connector andprevents balloon inflation prior to removal. Alternatively, the safetymember comprises a safety guard that snaps onto a proximal end of theballoon catheter and has a toggle lever that pivots to a positionbetween the balloon catheter and the proximal end of the handpiece,wherein outward pivoting of the toggle lever permits distal movement ofthe balloon catheter, and distal movement of the balloon catheter andattached safety guard enables removal of the safety guard so as toprevent balloon inflation prior to distal movement of the ballooncatheter.

Another disclosed system for delivering an exemplary hybrid prostheticheart valve includes a valve holder attached to the heart valve andhaving a bore, and an integrated assembly of a handle shaft and ballooncatheter. The assembly has a handle shaft with a handpiece on a proximalend and a distal adapter configured to mate with a proximal end of thevalve holder. The axial positions of the handpiece and adapter arefixed, and the handle shaft and handpiece define a handle lumen. Aballoon catheter having a balloon is received within the handle lumenand has a proximal balloon displacer for manually displacing thecatheter relative to the handle lumen and a proximal luer connector forattaching a fluid fill tube to inflate the balloon. The balloon catheterhas two primary positions relative to the handpiece—a retracted positionwherein the balloon displacer is spaced from the handpiece and theballoon resides partly within the handle shaft adapter and an advancedposition where the balloon displacer engages the handpiece and theballoon extends distally from the handle shaft adapter and is positionedwithin the expandable frame. A safety member engaged between the ballooncatheter and the handpiece prevents distal movement of the ballooncatheter from its retracted position.

A preferred method of delivery and implant of a hybrid prosthetic heartvalve system comprises:

-   -   providing a delivery system including a handle shaft having a        lumen therethrough, and wherein an expansion catheter extends        through the handle shaft and has an expandable member on a        distal end and a proximal end projecting proximally from out of        the handle shaft, the expansion catheter being capable of linear        movement relative to the handle shaft;    -   providing a hybrid heart valve with a valve member and        expandable frame;    -   advancing the delivery system so that the heart valve with the        frame in its contracted state is located at an implant position        adjacent the annulus;    -   displacing a safety member from engagement between a portion of        the expansion catheter that projects from the handle shaft and a        proximal end of the handle shaft, the safety member preventing        distal movement of the expansion catheter relative to the handle        shaft prior to displacement;    -   displacing the expansion catheter distally so that the        expandable member is located within the heart valve frame; and    -   expanding the expandable member to expand the frame.

The safety member may comprise a locking clip that snaps onto thehandpiece and proximal end of the expansion catheter preventing relativeballoon catheter handpiece movement prior to removal, wherein the methodincludes removing the locking clip prior to the step of displacing theexpansion catheter distally. If the expansion catheter is a ballooncatheter with a proximal luer connector, the locking clip also coversthe luer connector and prevents balloon inflation prior to removal, andthe method includes removing the locking clip prior to the step ofdisplacing the expansion catheter distally and displacing the expansioncatheter distally prior to inflating the balloon.

In one embodiment, the safety member comprises a safety guard having astationary part that snaps onto a proximal end of the handpiece and amovable part that forms the proximal end of the balloon catheter and hasthe luer connector. An elongated arm on the stationary part terminatesin a luer guard that receives the luer connector in the retractedposition of the balloon catheter and prevents coupling of a mating luerconnector of a fluid source thereto. Accordingly, distal movement of theballoon catheter and movable part exposes the luer connector to permitcoupling of a mating luer connector, and the method includes advancingthe balloon catheter and movable part prior to inflating the balloon.

The native valve leaflets may be removed before delivering theprosthetic valve. Alternatively, the native leaflets may be left inplace to reduce surgery time and to provide a stable base for fixing theanchoring skirt within the native valve. In one advantage of thismethod, the native leaflets recoil inward to enhance the fixation of themetallic anchoring skirt in the body channel. When the native leafletsare left in place, a balloon or other expansion member may be used topush the valve leaflets out of the way and thereby dilate the nativevalve before implantation of the anchoring skirt. The native annulus maybe dilated between 1.0-5 mm from their initial orifice size toaccommodate a larger sized prosthetic valve.

In accordance with a preferred aspect, a heart valve includes aprosthetic valve defining therein a non-expandable, non-collapsibleorifice, and an expandable anchoring skirt extending from an inflow endthereof. The anchoring skirt has a contracted state for delivery to animplant position and an expanded state configured for outward connectionto the surrounding annulus. Desirably, the anchoring skirt isplastically expandable.

In one embodiment, the heart valve comprises a commercially availableprosthetic valve having a sewing ring, and the anchoring skirt attachesto the sewing ring. The contracted state of the anchoring skirt may beconical, tapering inward from the first end toward the second end, whilein the expanded state the frame is conical but tapering outward from thefirst end toward the second end. The anchoring skirt preferablycomprises a plurality of radially expandable struts at least some ofwhich are arranged in rows. The sewing ring may comprise a solid yetcompressible material that is relatively stiff so as to provide a sealagainst the annulus and has a concave inflow shape that conforms to theannulus.

One method of the application involves increasing the orifice size ofthe heart valve annulus by 1.0-5.0 mm by plastically expanding theframe. In one embodiment, the prosthetic valve of the valve component isselected to have an orifice size that matches the increased orifice sizeof the heart valve annulus.

One embodiment of the method further includes mounting the heart valveon a holder having a proximal hub and lumen therethrough. The holdermounts on the distal end of a handle shaft having a lumen therethrough,and the method includes passing a balloon catheter through the lumen ofthe handle shaft and the holder and within the heart valve, andinflating a balloon on the balloon catheter to expand the anchoringskirt. The heart valve mounted on the holder may be packaged separatelyfrom the handle shaft and the balloon catheter. The delivery systemincluding the valve holder is designed to position the balloon withinthe heart valve so that it inflates within the anchoring skirt, and notwithin the actual valve components. A safety member is displaced fromengagement between a proximal portion of the balloon catheter and aproximal end of the handle shaft, the safety member preventing distalmovement of the balloon catheter relative to the handle shaft prior todisplacement.

Preferably, a valve delivery system includes an integrated ballooncatheter and tubular handle shaft through which the catheter extends. Adistal end of the handle shaft includes an adapter which mates with aholder of the heart valve, and a locking sleeve for rapidly connectingthe delivery system to the heart valve holder. A balloon of the ballooncatheter resides within the adapter and may be advanced distally intoposition for expanding the anchoring skirt. A tubular balloon introducersleeve attached when removing the heart valve from a storage jarfacilitates passage of the balloon through the heart valve.

A further understanding of the nature and advantages of the presentinvention are set forth in the following description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained and other advantages and featureswill appear with reference to the accompanying schematic drawingswherein:

FIG. 1A is a perspective cutaway view of an aortic annulus showing aportion of the adjacent left ventricle below the ascending aorta,illustrating an exemplary surgical heart valve mounted on a distalsection of a delivery handle advancing into position within the aorticannulus along the guide sutures;

FIG. 1B is a view similar to FIG. 1A illustrating the heart valve in adesired implant position at the aortic annulus, and during placement ofsuture snares;

FIG. 2A is an enlarged view of the aortic valve implant site showing theballoon of the balloon catheter inflated to expand the anchoring skirt,while FIG. 2B shows the balloon deflated and stretched;

FIGS. 3 and 3A are elevational and broken longitudinal sectional views,respectively, of the heart valve delivery system with a balloon catheterin a retracted position;

FIGS. 4 and 4A are elevational and broken longitudinal sectional views,respectively, of the heart valve delivery system with the ballooncatheter in an extended position;

FIG. 5A is a partial sectional view of the heart valve delivery systemhaving the prosthetic heart valve and valve holder thereon and in theballoon advanced configuration of FIG. 4A;

FIG. 5B is a partial sectional view similar to FIG. 5A and showingmovement of a balloon extension wire to compress a spring upon ballooninflation;

FIG. 5C is similar to FIG. 5A and shows return movement of the balloonextension wire and spring upon balloon deflation;

FIG. 6 is a perspective view of the proximal end of the exemplary heartvalve delivery system of the present application showing a locking clipexploded therefrom, while FIGS. 7A and 7B are elevational and brokenlongitudinal sectional views, respectively, of the heart valve deliverysystem with a balloon catheter held in the retracted position by thelocking clip;

FIGS. 8A-8C are views of an alternative embodiment for preventingpremature deployment of the balloon catheter in the valve deliverysystem using a toggle lever;

FIGS. 9-12 schematically illustrate alternative valve systems for fluidused to inflate the balloon on the catheter disclosed herein thatprevent premature deployment of the balloon;

FIG. 13 is a side elevational view of an exemplary heart valve deliverysystem having a safety clip attached on a proximal end that preventspremature inflation of a dilatation balloon;

FIGS. 14A-14C are perspective views of the safety clip of FIG. 13 inseveral deployment positions;

FIGS. 15A-15C illustrate a sequence of operation of the heart valvedelivery system having the safety clip of FIG. 13 thereon, while FIGS.16A-16C show the same sequence in longitudinal cross-section;

FIGS. 17A and 17B are perspective views of a still further safety guardof the present application showing a toggle lever in two differentpositions;

FIGS. 18A-18E are side elevational views of a proximal end of anexemplary heart valve delivery system having the safety guard of FIG.17A attached thereto and showing a sequence of operation;

FIGS. 19A and 19B are enlarged sectional views through a portion of thesafety guard and heart valve delivery system illustrating relativeengagement and disengagement thereof;

FIGS. 20A and 20B are perspective views of a still further safety guardof the present application showing interaction with a heart valvedelivery system with a balloon catheter in both retracted and advancedpositions;

FIGS. 21A-21E are side elevational and enlarged sectional views of thesafety guard of FIG. 20A attached to the heart valve delivery system andshowing operation thereof;

FIGS. 22A-22C are perspective and side elevational views of analternative safety guard similar to that shown in FIG. 20A and having anangled luer connector;

FIGS. 23A-23C are perspective and longitudinal sectional views through astill further alternative safety guard of the present application; and

FIGS. 24A-24C are side elevational views of an exemplary heart valvedelivery system and expandable/collapsible prosthetic valve, showing asequence of deployment thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention attempts to overcome drawbacks associated withconventional, open-heart surgery, while also adopting some of thetechniques of newer technologies which decrease the duration of thetreatment procedure. The prosthetic heart valves of the presentinvention are primarily intended to be delivered and implanted usingconventional surgical techniques, including the aforementionedopen-heart surgery. There are a number of approaches in such surgeries,all of which result in the formation of a direct access pathway to theparticular heart valve annulus. For clarification, a direct accesspathway is one that permits direct (i.e., naked eye) visualization ofthe heart valve annulus. In addition, it will be recognized thatembodiments of the prosthetic heart valves described herein may also beconfigured for delivery using percutaneous approaches, and thoseminimally-invasive surgical approaches that require remote implantationof the valve using indirect visualization. However, the latter twoapproaches—percutaneous and minimally-invasive—invariably rely oncollapsible/expandable valve constructs. And, while certain aspectsdescribed herein are useful for such valves and techniques, the primaryfocus and main advantages of the present application is in the realm ofnon-expandable “surgical” valves introduced in conventional manners.

As described herein, a “unitary” prosthetic heart valve includes atissue anchor connected to a surgical valve member resulting in certainadvantages. The unitary prosthetic heart valve disclosed herein is ahybrid valve member, if you will, with both non-expandable andexpandable portions. By utilizing an expandable anchoring skirt or stentcoupled to a non-expandable valve member, the duration of the anchoringoperation is greatly reduced as compared with a conventional sewingprocedure utilizing an array of sutures for a surgical valve. Theexpandable anchoring skirt may simply be radially expanded outward intocontact with the implantation site, or may be provided with additionalanchoring means, such as barbs. As stated, conventional open-heartapproach and cardiopulmonary bypass familiar to cardiac surgeons areused. However, due to the expandable anchoring skirt, the time on bypassis greatly reduced by the relative speed of implant in contrast to theprevious time-consuming knot-tying process.

For definitional purposes, the terms “stent” or “coupling stent” referto a structural component that is capable of anchoring to tissue of aheart valve annulus. The coupling stents described herein are mosttypically tubular stents, or stents having varying shapes or diameters.A stent is normally formed of a biocompatible metal frame, such asstainless steel or Nitinol. More preferably, in the context of thepresent invention the stents are made from laser-cut tubing of aplastically-expandable metal. Other coupling stents that could be usedwith valves of the present invention include rigid rings, spirally-woundtubes, and other such tubes that fit tightly within a valve annulus anddefine an orifice therethrough for the passage of blood. It is entirelyconceivable, however, that the coupling stent could be separate clampsor hooks that do not define a continuous periphery. Although suchdevices sacrifice some contact uniformity, and speed and ease ofdeployment, they could be configured to work in conjunction with aparticular valve member.

A distinction between self-expanding and balloon-expanding stents existsin the field. A self-expanding stent may be crimped or otherwisecompressed into a small tube and possesses sufficient elasticity tospring outward by itself when a restraint such as an outer sheath isremoved. In contrast, a balloon-expanding stent is made of a materialthat is substantially less elastic, and indeed must be plasticallyexpanded from the inside out when converting from a contracted to anexpanded diameter. It should be understood that the termballoon-expanding stents encompasses plastically-expandable stents,whether or not a balloon is used to actually expand it (e.g., a devicewith mechanical fingers could expand the stent). The material of thestent plastically deforms after application of a deformation force suchas an inflating balloon or expanding mechanical fingers. Consequently,the term “balloon-expandable stent” should be understood as referring tothe material or type of the stent as opposed to the specific expansionmeans.

The term “valve member” refers to that component of a heart valve thatpossesses the fluid occluding surfaces to prevent blood flow in onedirection while permitting it in another. As mentioned above, variousconstructions of valve members are available, including those withflexible leaflets and those with rigid leaflets, or even a ball and cagearrangement. The leaflets may be bioprosthetic, synthetic, metallic, orother suitable expedients. In a preferred embodiment, the non-expandablevalve member is an “off-the-shelf” standard surgical valve of the typethat has been successfully implanted using sutures for many years, suchas the Carpentier-Edwards PERIMOUNT Magna® Aortic Heart Valve availablefrom Edwards Lifesciences of Irvine, Calif., though the autonomousnature of the valve member is not absolutely required. In this sense, a“off-the-shelf” prosthetic heart valve is suitable for stand-alone saleand use, typically including a non-expandable, non-collapsible supportstructure having a sewing ring capable of being implanted using suturesthrough the sewing ring in an open-heart, surgical procedure.

Desirably, the present application includes delivery systems for aprosthetic heart valve having a single stage implantation in which asurgeon secures a hybrid valve having an anchoring skirt and valvemember to a valve annulus as one unit or piece (e.g., a “unitary”valve). Certain features of the hybrid anchoring skirt and valve memberare described in U.S. Pat. No. 8,308,798, filed Dec. 10, 2009, as wellas in U.S. Patent Publication No. 2012/0065729, filed Jun. 23, 2011, thecontents of which are expressly incorporated herein. It should be notedthat “two-stage” prosthetic valve delivery disclosed in theaforementioned publication refers to the two primary steps of a)anchoring structure to the annulus, and then b) connecting a valvemember, which does not necessarily limit the valve to just two parts.Likewise, the valve described herein is especially beneficial in asingle stage implant procedure, but that does not necessarily limit theoverall system to just one part. For instance, the heart valve disclosedherein could also use an expanding base stent which is then reinforcedby the subsequently implanted heart valve. Because the heart valve has anon-expandable and non-collapsible annular support structure, and aplastically-expandable anchoring skirt, it effectively resists recoil ofa self-expanded base stent.

As a point of further definition, the term “expandable” is used hereinto refer to a component of the heart valve capable of expanding from afirst, delivery diameter to a second, implantation diameter. Anexpandable structure, therefore, does not mean one that might undergoslight expansion from a rise in temperature, or other such incidentalcause such as fluid dynamics acting on leaflets or commissures.Conversely, “non-expandable” should not be interpreted to meancompletely rigid or a dimensionally stable, as some slight expansion ofconventional “non-expandable” heart valves, for example, may beobserved.

In the description that follows, the term “body channel” is used todefine a blood conduit or vessel within the body. Of course, theparticular application of the prosthetic heart valve determines the bodychannel at issue. An aortic valve replacement, for example, would beimplanted in, or adjacent to, the aortic annulus. Likewise, a mitralvalve replacement will be implanted at the mitral annulus. Certainfeatures of the present invention are particularly advantageous for oneimplantation site or the other, in particular the aortic annulus.However, unless the combination is structurally impossible, or excludedby claim language, any of the heart valve embodiments described hereincould be implanted in any body channel.

A “quick-connect” aortic valve bio-prosthesis described herein is asurgically-implanted medical device for the treatment of aortic valvestenosis. The exemplary quick-connect device comprises an implantablebio-prosthesis and a delivery system for its deployment. The device,delivery system and method of use take advantage of the provenhemodynamic performance and durability of existing commerciallyavailable, non-expandable prosthetic heart valves, while improving easeof use and reducing total procedure time. This is mainly accomplished byeliminating the need to suture the bio-prosthesis onto the nativeannulus as is currently done per standard surgical practice, andtypically requires 12-24 manually-tied sutures around the valveperimeter. Also, the technique may obviate the need to excise theleaflets of the calcified valve and debride or smooth the valve annulus.

An exemplary hybrid prosthetic heart valve and valve holder is disclosedin U.S. Patent Publication No. 2012/0065729 to Pintor, et al., filedJun. 23,2011, to which priority is claimed, and which is herebyexpressly incorporated by reference herein. For a more detaileddescription of the heart valve, reference is made to FIGS. 5-15 of thePintor publication.

As seen in FIGS. 1A-1B and 2A-2B, a prosthetic heart valve 20 isassembled on a valve holder 22. The heart valve 20 desirably includes avalve member 24 having an anchoring skirt 26 attached to an inflow endthereof, such as to a sewing ring 28. The valve member 24 is desirablynon-collapsible and non-expandable, while the anchoring skirt 26 mayexpand from the contracted state shown into an expanded state, as willbe described. In one embodiment, the valve member 24 comprises aCarpentier-Edwards PERIMOUNT Magna® Aortic Heart Valve available fromEdwards Lifesciences of Irvine, Calif., while the anchoring skirt 26includes an inner plastically-expandable frame or stent covered withfabric.

As seen in FIG. 2B (and in more detail in FIGS. 6-8 of the Pintorpublication), the valve holder 22 preferably includes a central tubularhub portion 30 having internal threads, and a plurality of stabilizinglegs 32 projecting axially and radially outward therefrom. Each of thethree stabilizing legs 32 contacts and attaches to a cusp portion of thevalve member 24 between commissure posts 36. An upper end of the hubportion 30 also has an internal star-shaped bore that provides avalve-size-specific keyed engagement with a delivery system. The valveholder 22 secures with sutures to the valve member 24 from the time ofmanufacture to the time of implant, and is stored with the valve member.

In one embodiment, the holder 22 is formed of a rigid polymer such asDelrin polypropylene that is transparent to increase visibility of animplant procedure. The holder 22 provides relatively wide openingsbetween the stabilizing legs 32 to provide a surgeon good visibility ofthe valve leaflets, and the transparency of the legs further facilitatesvisibility and permits transmission of light therethrough to minimizeshadows.

The completed valve member 24 provides the occluding surfaces for theprosthetic heart valve 20, preferably in the form of flexiblebioprosthetic leaflets. For example, the valve leaflets may be takenfrom another human heart (cadaver), a cow (bovine), a pig (porcinevalve) or a horse (equine). Alternatively, the valve member may comprisemechanical components rather than biological tissue. Although anautonomous (i.e., capable of stand-alone surgical implant) flexibleleaflet valve member 24 is described and illustrated, alternative valvemembers that have rigid leaflets, or are not fully autonomous may besubstituted.

For bioprosthetic valves, an exemplary process includes storing theprosthetic heart valve 20 in a preservative solution after manufactureand prior to use. A preservative such as glutaraldehyde is providedwithin a storage jar. This “wet” storage arrangement applies to theillustrated heart valve 20 shown, which includes conventionalbioprosthetic leaflets, but could also be used without a preservativesolution for bioprosthetic leaflets that have been dried and also formechanical valves.

The general function of the anchoring skirt 26 is to provide the meansto attach the prosthetic valve member 24 to the native aortic root. Thisattachment method is intended as an alternative to the present standardsurgical method of suturing aortic valve bio-prostheses to the aorticvalve annulus, and is accomplished in much less time. Further, thisattachment method improves ease of use by eliminating most of not allsuturing. The anchoring skirt 26 may be a pre-crimped, tapered, 316Lstainless steel balloon-expandable stent, desirably covered by apolyester fabric to help seal against paravalvular leakage and promotetissue ingrowth once implanted within the annulus. The anchoring skirt26 transitions between the tapered constricted shape of FIGS. 1A-1B toits flared expanded shape shown in FIGS. 2A-2B.

An exemplary implant procedure for the prosthetic heart valve 20 wasdisclosed with reference to FIGS. 16A-16J of the Pintor publication, aportion of which is shown in the present application in FIGS. 1A-1B and2A-2B. These figures are sectional views through an isolated aorticannulus showing a portion of the adjacent left ventricle and ascendingaorta with sinus cavities. The two coronary arteries are also shown. Aswill be explained, the anchoring skirt 26 is deployed against the nativeleaflets or, if the leaflets are excised, against the debrided aorticannulus as shown.

In the ensuing procedure drawings, the heart valve 20 is oriented withan inflow end down and an outflow end up. That is, blood flow throughthe valve 20 is upward as shown in the drawings. Therefore, the termsinflow side and down may be used interchangeably at times, as well asthe terms outflow side and up. Furthermore, the terms proximal anddistal are defined from the perspective of the surgeon delivering thevalve inflow end first, and thus proximal is synonymous with up or theoutflow side, and distal with down or the inflow side.

An implant procedure involves delivering the heart valve 20 andexpanding the anchoring skirt 26 at the aortic annulus. Because thevalve member 24 is non-expandable, the entire procedure is typicallydone using the conventional open-heart technique. However, because theanchoring skirt 26 is implanted by simple expansion, with reducedsuturing, the entire operation takes less time. This hybrid approachwill also be much more comfortable to surgeons familiar with theopen-heart procedures and commercially available heart valves.

A preliminary step in preparing an aortic annulus for receiving theheart valve includes installation of guide sutures 38. The aorticannulus is shown schematically isolated and it should be understood thatvarious anatomical structures are not shown for clarity. The annulusincludes a fibrous ring of tissue that projects inward from surroundingheart walls. The annulus defines an orifice between the ascending aortaand the left ventricle. Although not shown, native leaflets projectinward at the annulus to form a one-way valve at the orifice. Theleaflets may be removed prior to the procedure, or left in place asmentioned above. If the leaflets are removed, some of the calcifiedannulus may also be removed, such as with a rongeur. The ascending aortacommences at the annulus with three outward bulges or sinuses, two ofwhich are centered at coronary ostia (openings) leading to coronaryarteries. As will be seen below, it is important to orient theprosthetic valve member 24 so that its commissure posts 36 are notaligned with and thus not blocking the coronary ostia.

The surgeon attaches the guide sutures 38 at three evenly spacedlocations around the aortic annulus. In the illustrated embodiment, theguide sutures 38 attach to locations below or corresponding to thecoronary ostia (that is, two guide sutures are aligned with the ostia,and the third centered below the non-coronary sinus). The guide sutures38 are preferably looped twice through the annulus from the outflow orascending aorta side to the inflow or ventricular side. Of course, othersuturing methods or pledgets may be used depending on surgeonpreference.

FIG. 1A shows the heart valve 20 on the distal end of a delivery system110 and at a desired implant position at the aortic annulus, and duringplacement of tubular suture snares. The sewing ring 28 is positionedsupra-annularly, or above the narrowest point of the aortic annulus, soas to allow selection of a larger orifice size than a valve placedintra-annularly. A dilatation balloon 112 on the distal end of a ballooncatheter 114 of the delivery system 110 can be seen just beyond thedistal end of the anchoring skirt 26.

The surgeon delivers a plurality of suture snares 120 down each freelength of the guide sutures 38 into contact with the upper or outflowside of the sewing ring 28. The snares 120 enable downward pressure tobe applied to the ring 28 and thus the valve 20 during the implantprocedure, which helps insure good seating of the ring 28 on theannulus. The snares 120 also provide rigid enclosures around each of theflexible guide sutures 38 which helps avoid entanglement with othermoving surgical instruments, as will be appreciated. As there are threepairs of guide sutures 38 (six free lengths) three snares 120 areutilized, though more or less is possible. The snares 120 are typicallytubular straw-like members of medical grade plastic.

FIG. 1A shows all of the pairs of suture snares 120 bent outward and amajority of the delivery system 110. The delivery system 110 is in aconfiguration prior to advancement of the balloon catheter 114 and itsdilatation balloon 112.

FIG. 1B shows the delivery system after advancement of the ballooncatheter 114 and dilatation balloon 112 relative to a handpiece 204 on aproximal end of an elongated handle shaft 130. Although it will bedescribed in greater detail below with respect to FIGS. 3-5, the handleshaft 130 terminates in a valve holder adapter 208 that directlyconnects to the holder 22. The handle shaft 130 is desirably malleablefor manipulating the orientation of the heart valve 20 during deliverythrough the ascending aorta.

After distal advancement, the balloon 112 projects downward through thevalve 20, and into the left ventricle. As will be explained below, thedelivery system 110 provides binary position displacement of the balloon112, either retracted substantially within the prosthetic heart valve 20or advanced precisely as far as necessary to expand the anchoring skirt26 of the valve.

FIG. 2A shows the dilatation balloon 112 inflated to expand theanchoring skirt 26 against the ventricular side of the aortic annulus.The balloon 112 desirably has a frustoconical profile that expands theanchoring skirt 26 into a frustoconical expanded state. Not only doesthis conform better to the subannular contours but over expands somewhatthe annulus such that a larger valve maybe utilized than without theexpansion. One advantage of using a plastically-expandable stent is theability to expand the native annulus to receive a larger valve size thanwould otherwise be possible with conventional surgery. Desirably, theleft ventricular outflow tract (LVOT) is significantly expanded by atleast 10%, or for example by 1-5 mm, and the surgeon can select a heartvalve 20 with a larger orifice diameter relative to an unexpandedannulus. Even a 1 mm increase in annulus size is significant since thegradient is considered to be proportional to the radius raised to the4th power.

Simple interference between the anchoring skirt 26 and the annulus maybe sufficient to anchor the heart valve 20, or interacting features suchas projections, hooks, barbs, fabric, etc. may be utilized. For example,a distal end of the anchoring skirt may expand more than the rest of theanchoring skirt so that peaks in the strut row farthest from theprosthetic valve project outward into the surrounding annulus. Also, theballoon 112 may have a larger distal expanded end than its proximalexpanded end so as to apply more force to the free end of the anchoringskirt 26 than to the prosthetic valve member 24. In this way, theprosthetic valve member 24 and flexible leaflets therein are not subjectto high expansion forces from the balloon 112.

The balloon 112 desirably is tapered to have an angle between about0-45°, and more preferably is about 38° (0° being a cylindricalexpansion). Alternatively, the balloon 112 may include curves ornon-axi-symmetric contours to deform the anchoring skirt 26 to variousdesired shapes to fit better within the particular annulus. Indeed,various potential shapes are described in U.S. Patent Publication2008/0021546, entitled System for Deploying Balloon-Expandable HeartValves, published Jan. 24,2008, the disclosure of which is expresslyincorporated herein.

FIG. 2B then illustrates the balloon 112 deflated and contracted. Aspring mechanism within the delivery system 110 along with longitudinalpleats in the balloon 112 facilitate contraction of the balloon whendeflated into an extremely narrow configuration which makes removaleasier.

The next step is retraction of the balloon 112 and entire deliverysystem 110 from the valve holder 22 before or after removal of thesnares 120, which happens only as a contingency. Although not shown, themost common procedure after expansion of the balloon 112 and skirt 26involves the surgeon severing the connecting sutures between the valveholder 22 and the prosthetic valve member 24, and removing the entiredelivery system. Severing a middle length of each suture that connectsthe holder 22 to the valve member 24 permits the delivery system 110with the holder at the distal end to be pulled free from the valve 20.However, the delivery system 110 also features a simple engagement anddetachment mechanism explained below that enables the surgeon to easilyremove the system 110 from the holder 22 which remains attached to thevalve 20. This detachment may be needed to replace the balloon catheter,such as if the original balloon develops a leak or for some reason doesnot deploy properly. This “quick-release” arrangement permits thesurgeon to rapidly exchange catheters while leaving the valve 20 inplace.

Finally, the prosthetic heart valve 20 is fully implanted with the guidesutures 38 knotted on the proximal face of a sewing ring 28. The guidesutures 38 are primarily for rotationally orienting the heart valve 20as it seats against the aortic annulus and to define a plane for axialpositioning. As such, the guide sutures 38 are not believed strictlynecessary for securing the heart valve 20 at the annulus. Moreover,devices other than knots such as clips or cinches could be used tosecure the guide sutures 38 speed up the process.

FIGS. 3-3A and 4-4A show the prosthetic heart valve delivery system 110in elevational and sectional views, in both the retracted and advancedpositions of the balloon catheter 114. On its proximal end, the system110 includes an end cap 190 having a luer connector 192, a balloonextension spring 194, a spring compression pin 196, a balloon displacer198, an inflation tube 199, and a balloon extension wire 200. Themid-portion of the system 110 includes a centering washer 202, thehandpiece 204, and the aforementioned malleable handle shaft 130.Finally, distal components of the system 110 include a tubular lockingsleeve 206, the valve holder adapter 208, the dilatation balloon 112,and an insert molded tip 210. The entire system preferably has a lengthfrom the proximal end of the luer connector 192 to the balloon wire tip210 of between about 100 and 500 mm.

FIGS. 3 and 3A show the end cap 190 and balloon displacer 198 joinedtogether, preferably with adhesive or other such coupling means. Theassembly of the end cap 190 and balloon displacer 198 forms a handle ofthe balloon catheter 114 and may be displaced linearly with respect tothe handpiece 204. The malleable handle shaft 130 extends distally fromthe handpiece 204 and is preferably secured thereto with adhesive or thelike. The valve holder adapter 208 fixes to a distal end of the handleshaft 130, but the locking sleeve 206 slides over the handle. In thisregard, the balloon catheter 114 slides linearly along and within the“introducer” comprising the handpiece 204, handle shaft 130, and valveholder adapter 208, as seen in FIGS. 4 and 4A.

When assembled as seen in FIG. 3A, an elongated lumen (not numbered)extends from the proximal luer connector 192 to the interior of theballoon 112. The luer connector 192 provides an attachment nipple for aninflation system (not shown) for inflation of the balloon 112. Theballoon 112 is desirably inflated using controlled, pressurized, sterilephysiologic saline. The lumen passes through the end cap 190, balloondisplacer 198, and then through the inflation tube 199 which is affixedat one end to the displacer and at another end to a proximal end of theballoon. The balloon displacer 198 thus moves the proximal end of theballoon.

The balloon catheter 114 of the delivery system 110 has two binarylongitudinal positions relative to the handpiece 204 and its associatedstructures. In the retracted position shown in FIGS. 3 and 3A, theconnected end cap 190, balloon displacer 198, inflation tube 199, andballoon 112 are retracted to the left with respect to the handpiece 204.Note the spacing A between a distal shoulder 230 of the balloondisplacer 198 and the centering washer 202 within the handpiece 204. Theballoon 112 resides partway within the holder adapter 208 in thisposition. Once the balloon catheter is displaced to the right, as seenin FIGS. 4 and 4A, the spacing A disappears and the balloon 112 projectsout from within the handle adapter 208.

The delivery system 110 provides an extremely accurate system forpositioning the balloon 112 relative to the heart valve, and inparticular the anchoring skirt 26. Because of the simple engagementbetween the handle adapter 208 and the handle shaft 130, very littletolerance errors are introduced. The handle adapter 208 is fixed to theelongated handle shaft 130, which in turn is fixed to the handpiece 204.Movement of the balloon catheter 114 relative to the handpiece 204 thusdisplaces the balloon 112 in a 1:1 correspondence with respect to theholder 22 and attached heart valve 20. Furthermore, a pair of smallresilient détentes 232 provided on the balloon displacer 198 engagesimilarly sized cutouts 234 on the proximal end of the handpiece 204.This locks the position of the balloon catheter 114 with respect to thehandpiece 204, or in other words locks the position of the balloon 112with respect to the anchoring skirt 26.

One aspect of the present application is the integration of a ballooncatheter within the delivery system 110. Namely, previous systems fordelivering prosthetic heart valves in this manner have included separateintroducer and balloon catheter elements, where the balloon catheterinserts through the tubular introducer. Although such a system may worksuitably for its intended purpose, an integrated balloon catheter 114within the delivery system 110 provides distinct advantages. First ofall, if there is a problem with the balloon, such as a puncture, thesurgeon need not retract the entire balloon catheter 114 through theintroducer and replace it with another one, which is time consuming.Instead, the delivery system 110 is merely decoupled from the valveholder 22, and a replacement delivery system 110 including a new ballooncatheter 114 engaged to the holder. Secondly, and perhaps more evident,a single delivery system 110 replacing multiple parts speeds up theentire process and facilitate ease-of-use. The surgeon no longer has tocouple multiple parts together prior to attaching to the heart valveholder, or manipulate a separate balloon catheter relative to anintroducer tube. Sliding a balloon catheter through an elongatedintroducer opens up the risk of snags and balloon tears. Finally, theamount of packaging is reduced accordingly.

FIGS. 5A-5C illustrate a preferred configuration for coupling thedelivery system 110 to the prosthetic heart valve 20 and holder 22assembly. In particular, a tubular balloon introducer sleeve 212 threadswithin the holder 22. Preferably, the user couples the introducer sleeve212 to the holder 22 at the time of preparing the valve 20 for surgery,and more preferably the sleeve 212 may be used to extract the valve 20from its storage jar. A portion of the sleeve 212 projects in a proximaldirection from within the holder 22 and presents a tubular entryway forthe balloon wire tip 210 and balloon 112. The user inserts the deliverysystem 110 through the introducer sleeve 212 until the valve holderadapter 208 contacts the holder 22.

With reference to FIGS. 3A and 5A, the valve holder adapter 208 includesan elongated through bore 214 which receives the proximal end of theintroducer sleeve 212. Although not shown, a plurality of cantileveredfingers extend longitudinally along the adapter 208 terminating at itsdistal end. Each of the fingers includes an inwardly directed bump 218(FIG. 5A). Sliding the adapter 208 over the introducer sleeve 212 suchthat the distal end contacts a proximal end of the holder 22 brings thebumps 218 over an external groove (not numbered) on the exterior of thesleeve 212 so as to provide an interference connection. The lockingsleeve 206 then slides over the holder adapter 208, as seen in FIG. 5A.Because the inner bore of the locking sleeve 206 fits closely around theadapter 208, the cantilevered fingers are retained in their alignedorientation with the bumps 218 in the groove of the sleeve 212. Thelocking sleeve 206 desirably frictionally engages the exterior of theadapter 208 to prevent two parts from easily coming apart.Alternatively, a separate detente or latch may be provided for moresecurity. Ultimately, when the locking sleeve 206 is in the position ofFIG. 5A, the delivery system 110 is securely coupled to the valve holder22. Moreover, the balloon 112 extends through the balloon introducersleeve 212 to be positioned within the expandable skirt 26.

Another advantageous feature of the present application is a keyedengagement between delivery systems 110 and holders 22 for the same sizeof heart valves. In particular, the hub portion 30 of the holder 22 hasan internal star-shaped bore (not shown) which is sized and patterned tobe keyed to an external star-shaped rim 220 provided on the holderadapter 208 (see FIG. 4). Because the balloon catheter 114 is integratedwith the delivery system 110, and each balloon catheter is sized for aparticular valve, only the delivery system 110 which is designed forthat particular valve should be coupled to its holder. That is, eachexpansion skirt 26 must be expanded to a particular diameter, whichrequires different sizes of balloons 112. Consequently, each differentlysized valve holder and a delivery system combination has a uniquestar-shaped pattern which prevents mating with a different size.

Typically, the delivery system 110 is packaged separately from the heartvalve 20 and holder 22, and this keying arrangement prevents misuse ofthe wrong delivery system. Additionally, if the balloon breaks andanother delivery system must be rapidly obtained and utilized, thekeying arrangement prevents the wrong delivery system from beingsubstituted. There are typically 6-8 valve sizes in 2 millimeterincrements, and thus a similar number of unique keyed couplings will beprovided. Furthermore, the star-shaped pattern disclosed permitsengagement at a plurality of rotational orientations. In a preferredembodiment, the user must rotate the delivery system 110 no more than30° before the star-shaped rim 220 of the adapter 208 mates with theinternal star-shaped bore of the holder 22. This is extremely beneficialif changing out the delivery system 110, because the original elongatedhandle shaft 130 may be bent into a particular orientation which is mucheasier to replicate if the keyed features do not have to be oriented inonly one or two angular relations.

As mentioned, the elongated handle shaft 130 is malleable or bendableinto various shapes. This bendability of the handle shaft 130significantly enhances the ability of a surgeon to correctly positionthe heart valve 20 as it advances toward the annulus. Often, accesspassageways into the heart during a surgical procedure are somewhatconfined, and may not provide a linear approach to the annulus.Accordingly, the surgeon bends the handle shaft 130 to suit theparticular surgery. Various materials and constructions may be utilizedto provide a malleable tube for use as the handle shaft 130. The handleshaft 130 must be axially rigid so that the user can position the heartvalve in the annulus with confidence. In a preferred embodiment, analuminum tube having a chromate (e.g., Iridite) coating is used.Aluminum is particularly well-suited for forming small tubes that can bebent without kinking, but should be coated with Iridite or the like toprevent deterioration in and reaction with the body.

The balloon inflation tube 199 and balloon extension wire 200 are formedof materials that have column strength but are relatively flexible inbending. As explained further below, the wire may be Nitinol while theinflation tube 199 is desirably formed of a braid reinforcedthermoplastic elastomer (TPE) such as a polyether block amide knownunder the trade name of PEBAX® (Arkema of Colombes, France).

As the delivery system 110 may be subjected to several bends in use,care must be taken to ensure that the concentric tubes and wire do notintroduce misalignment. That is, smaller diameter objects tend to travelshorter paths within larger concentric tubes, thus cause them to extendout of the distal end of the tubes after being bent. As such, theballoon inflation tube 199 is desirably closely sized to match the innerdiameter of the malleable handle shaft 130. This close matching of tubesizes ensures that the axial position of the balloon 112, which isaffixed to the end of the balloon inflation tube 199, does not shiftmuch relative to the axial position of the prosthetic heart valve 20,which is affixed relative to the end of the malleable handle shaft 130.The balloon extension wire 200 has a size relative to the ID of theballoon inflation tube 199 sufficient to permit good flow of saline whenfilling the balloon 112.

The present application also provides an improved balloon 112 and systemfor deploying and removing it. As seen in the deflated views, theballoon 112 preferably comprises a plurality of longitudinal pleatswhich help reduce its radial configuration for passage through thedelivery system 110. Furthermore, the balloon extension wire 200 extendsthrough the balloon inflation tube 199, through the dilatation balloon112, and terminates in a molded balloon wire tip 210 affixed to thedistal end of the balloon. The path of the wire 200 is seen in thesectional views of FIGS. 3A and 4A. Although the proximal end of theballoon 112 fastens to the inflation tube 199, and thus from there tothe handpiece 204, the distal tip 210 does not. Instead, the wire 200fastens to the spring compression pin 196 which translates within alumen in the proximal end cap 190, and engages the balloon extensionspring 194 therein. In this regard, the balloon extension wire 200 movesindependently within the delivery system 110 instead of being fixedlyattached. This, in turn, allows the distal end of the balloon 112 tomove with respect to the proximal end. This arrangement is seen best inFIGS. 5A-5C.

The exemplary delivery system balloon 112 has a relatively highdiameter-to-length ratio compared to other surgical balloons, such asthose used to expand cardiovascular stents. This makes it particularlydifficult for the balloon 112 to return to a small geometry upondeflation after deployment. Balloons of such size ratios tend to“butterfly” by forming wings that prevent removal through the valveholder without the application of high forces, which may cause damage tothe valve itself. The exemplary delivery system 110 and balloon 112include several advances from earlier heart valve delivery systems thatfacilitate atraumatic removal of the balloon 112. First, as mentionedabove, a series of longitudinal pleats are heat set into the wall of theballoon 112 to facilitate self-collapse during deflation. Further, thedistal end of the balloon 112 moves relative to the proximal end toenable lengthening of the balloon during deflation. This lengtheningoccurs automatically by virtue of the wire 200 which is spring-biased tostretch the balloon longitudinally. It should be noted that easydeflation and removal of the balloon 112 permits rapid replacement ofthe balloon catheter in case of a problem, such as insufficientinflation.

FIG. 5A is a sectional view with the balloon 112 advanced as in FIG. 4A.In this configuration, the spring 194 has a length of x₁, and the springcompression pin 196 is all the way to the right within the end capcavity. In this “resting” state with the balloon 112 deflated, thespring 194 may be relaxed or under a slight compressive preload.Subsequently, saline is introduced via the proximal luer connector 192and travels distally along the length of the balloon catheter componentsto inflate the balloon 112. Inflation of the balloon 112 causes radialexpansion but axial foreshortening, thus displacing the distal tip 210to the left as shown in FIG. 5B. This, in turn, displaces the balloonextension wire 200 and attached spring compression pin 196 to the leftagainst the resiliency of the spring 194. Ultimately, the spring iscompressed to a second shorter length x₂. In a preferred embodiment, thespring 194 undergoes complete compression to its solid length so as toprovide a positive stop on proximal movement of the wire 200 andattached balloon distal tip 210. This helps ensure proper expansion ofthe anchoring skirt 26, as will be more fully explained. The proximalmovement of the distal tip 210 against the reaction force of the spring194 places the wire 200 in compression.

Finally, FIG. 5C illustrates deflation of the balloon 112 by pulling avacuum through the inflation movement and return movement to the rightof the distal tip 210 and balloon extension wire 200. This movement isencouraged, and indeed forced, by expansion of the spring 194. The forceof the spring 194 is calibrated so as to elongate the pleated balloon112 so it assumes its previous radially constricted diameter, or asclose as possible to it. Furthermore, the wire 200 may be rotated aboutits axis to further encourage constriction of the balloon 112 by causingthe pleats to further fold in a helical fashion. This can beaccomplished by extending a portion of the wire 200 from the proximalend of the Luer connector 192 so as to be grasped and rotated byforceps, or otherwise providing a lever or thumb plunger (not shown)fastened to the wire and projecting laterally from the system. Stillfurther, the spring compression pin 196 may be constrained to translatewithin a helical track. In the latter case, the pin 196 may include abayonet-type mount that locks within detents in both ends of the helicaltrack. The spring-biased lengthening and consequent radial contractionof the balloon 112 facilitates its proximal removal through thenow-deployed prosthetic heart valve 20.

As mentioned above, the balloon 112 desirably has a frustoconicalprofile that expands the anchoring skirt 26 into a frusto-conicalexpanded state. More typically, and as shown in FIG. 5B, the balloon 112is generally spherical when expanded. Nevertheless, a spherical balloonwill outwardly expand the anchoring skirt 26 into a frusto-conical shapedue to the connection at one end of the inner stent frame 80 to theheart valve sewing ring 28. To ensure sufficient and proper outwardexpansion of the anchoring skirt 26, the balloon 112 is axiallypositioned such that a midline 280 indicated around the maximumcircumference (equatorial line) thereof registers with the distalmostend 282 of the skirt. In doing so, the widest part of the balloon 112corresponds to the end of the skirt 26, which tends to expand the skirtconically. A tolerance of 1-2 mm between the location of the midline 280and the distalmost end 282 of the skirt is acceptable which may occurfor different sizes of valves and associated skirt 26.

FIG. 5A shows an exemplary stepped balloon construction wherein theballoon 112 is desirably offset molded to form the midline 280 as asmall step in the balloon wall. That is, the opposed balloon mold halveswill have a slightly different diameter, such that a physical step inthe final product is formed—the midline 280. Alternatively, the midline280 may be formed by a small equatorial rib or indent formed in the moldprocess, or even with an ink marking, though the latter may not besuitable for surgical application. The midline 280 will be visible onthe balloon 112 in both its deflated and inflated states, and isextremely useful as a reference line during assembly and quality controlof the delivery system 110. For instance, the components of the system110 are assembled and the location of the balloon 112 in its advancedposition is checked against the anchoring skirt 26. Since the balloon112 foreshortens when it is inflated, the reference midline 280 shouldbe beyond the distalmost end 282 of the skirt 26 when the balloon isdeflated, a location that can easily be inspected during assembly.

It should be mentioned that as an alternative to a balloon, a mechanicalexpander may be used to expand the anchoring skirt 26 shown above. Forinstance, a mechanical expander may include a plurality of spreadablefingers actuated by a syringe-like apparatus, as seen in U.S. Pat. No.8,308,798, filed Dec. 10, 2009, incorporated above. The fingers areaxially fixed but capable of pivoting or flexing with respect to abarrel. The distal end of a plunger has an outer diameter that isgreater than the diameter circumscribed by the inner surfaces of thespreadable fingers, such that distal movement of the plunger withrespect to the barrel gradually cams the fingers outward within thecoupling stent. Alternatives include mechanical fingers that are notpivotally attached to a handle attachment member. In this way, aninflation balloon causes direct radial expansion of the fingers insteadof a pivoting movement. Therefore, the term “expansion catheter”pertains to balloon catheters, purely mechanical spreaders on the end ofa catheter, or combinations thereof. Also, “plastically-expandable”encompasses materials that can be substantially deformed by an appliedforce, such as by a balloon or a mechanical spreader, to assume adifferent shape. Some self-expanding stents may be deformed to a degreeby an applied force beyond their maximum expanded dimension, but theprimary cause of the shape change is elastic rebound as opposed to aplastic deformation.

The present delivery system advantageously prevents prematureadvancement of the balloon catheter (or expander) so that the balloon112 remains retracted within the confines of the prosthetic heart valve20 during advancement of the valve into position within the aorticannulus. As will be readily apparent, the surgeon advances the entiredelivery system 110 with the heart valve 20 at its distal end throughthe open chest cavity or port and through the aortic arch and down theascending aorta into the implant position. Pushing on the proximal endof the delivery system 110 carries the risk of accidentally displacingthe balloon catheter 114 relative to the handpiece 204 prior to thedesired deployment stage. A protruding balloon 112 may damage thecoronary ostia or make insertion difficult by enlarging the deviceprofile. Consequently, the present application contemplates variousmeans for physically preventing movement of the balloon catheter,preferably coupled with a visual reminder not to deploy the catheterprematurely.

For instance, FIG. 6 is a perspective view of the proximal end of theexemplary heart valve delivery system 110 showing a locking clip 240attached thereto. As seen in FIGS. 7A and 7B, the locking clip 240 snapsto the exterior of the end cap 190 and handpiece 204 and holds theballoon catheter in a retracted position by presenting a physicalbarrier to relative movement of those two elements. The locking clip 240includes a semi-tubular body 242 terminating in a thumb ledge 244 on itsdistal end. The semi-tubular body 242 has internal features that matchthe external features on the handpiece 204. Specifically, although notshown, the interior of the semi-tubular body 242 has circumferentialridges that engage the proximal end of the handpiece 204 and bothfrictionally engage the handpiece and provide an impediment to distalaxial movement of the clip 240 relative to the handpiece. The lockingclip 240 bifurcates into two elongated rails 246 that extend proximallyfrom the body 242 and come together at a proximal bridge 248 having aninwardly-directed node 250 (FIG. 7B). The node 250 fits closely withinthe lumen of the luer connector 192 and provides a physical barrier andvisual indicator to prevent premature attachment of a balloon inflationsource. Further, interior features on the two elongated rails 246 engagematching contours on the balloon catheter end cap 190.

The clip 240 assembles to the delivery system 110 as shown with theballoon catheter in the retracted position (i.e., the position shown inFIG. 3). First the node 250 inserts into the luer connector 192 lumen,and then the clip 240 snaps over the end cap 190 and handpiece 204. Theconnection between the clip 240 and delivery system 110 is frictionaland the clip can easily be removed, but provides a physical barrier andvisual reminder to prevent premature distal deployment of the ballooncatheter 114, as well as prevents connection of a balloon inflationsource. Furthermore, the thumb ledge 244 on the clip 240 provides aconvenient ergonomic feature that facilitates one-handed control of thesystem advancement. After the surgeon advances the system and prostheticheart valve 20 into position within the aortic annulus, he/she removesthe clip 240 to enable deployment of the balloon catheter 114 andconnection of an inflation source. The clip 240 is typically plastic andis discarded.

Other possible barriers to premature balloon catheter deployment/ballooninflation are contemplated. In one configuration shown in FIGS. 8A-8C, atoggle lever 260 connects to both the end cap 190 and handpiece 204 andmay be displaced in either direction to alternately deploy and retractthe balloon catheter. More specifically, the toggle lever 260 includes athumb piece 262 that projects outward from the delivery system 110, ahinge 264 pivotally mounted to the handpiece 204, and a blocking end 266that fits in the axial space between the end cap 190 and handpiece 204in the retracted position of Figure 8A. A linkage bar 268 pivotallyattaches midway along the thumb piece 262 and pivotally attaches at itsopposite end to the end cap 190.

The retracted position of FIG. 8A corresponds to the retracted positionof the balloon catheter 114 in the delivery system 110 as in FIG. 3. Inthis state, the blocking end 266 fits closely between the facingsurfaces of the spaced-apart end cap 190 and handpiece 204, and thuspresents a physical barrier to distal advancement of the end cap andballoon catheter within the delivery system 110. At the appropriatemoment, the surgeon pivots the toggle lever 260 in the direction of thearrow 270 in FIG. 8B, which simultaneously removes the blocking end 266from between the end cap 190 and handpiece 204 and pulls the end captoward the handpiece by virtue of the linkage bar 268. Pivoting thetoggle lever 260 the full extent of its travel completely deploys theballoon catheter 114 and displaces the balloon 112 to its properposition within the anchoring skirt 26. That is, the distance traveledby the end cap 190 relative to the handpiece 204 is calibrated to beprecisely the same distance necessary to advance the balloon 112 to alocation for proper expansion of the anchoring skirt 26 that ensures itsoptimum hemodynamic performance. Consequently, not only does the togglelever 260 prevent premature deployment of the balloon catheter, but italso ensures advancement thereof prior to balloon inflation, and in sodoing ensures accurate advancement. Additionally, due to the connectednature of the toggle lever 260, there are no loose parts to interferewith the procedure or potentially be misplaced during the surgery.Further details on ensuring the correct positioning of the balloon 112within the skirt 26 are provided below.

When the surgeon pushes the toggle lever 260 into the advanced position,it desirably snaps into some feature on the handpiece 204 to signalcomplete deployment and to hold it in place. For instance, FIG. 8C showsa distal tip 272 of the lever 260 captured in a complementary notch orrecess in the exterior of the handpiece 204. Of course, numerous othersuch configurations are possible, and in general the toggle lever 260and its interaction with the end cap 190 and handpiece 204 are exemplaryonly. Alternatives such as sliders, rotating knobs or levers, colored oreven lighted indicators, etc., are contemplated. The purpose of suchalternatives is to prevent premature advancement of the ballooncatheter, ensure advancement before balloon inflation, and ensureaccurate advancement within the anchoring skirt 26 of the prostheticheart valve 20.

Other devices to prevent premature balloon catheter deployment/ballooninflation are contemplated, including physical impediments such as thetoggle lever 260 described above as well as visual or audible indicatorsto prevent deployment. For instance, an alternative configuration thatimpedes balloon inflation fluid flow prior to catheter advancement isseen in FIGS. 9-12, which schematically illustrate systems where a portfor fluid used to inflate the balloon on the catheter must be firstopened prior to balloon expansion.

FIG. 9 is an elevational view of a portion of the proximal end of analternative delivery system 110 similar to the views of FIGS. 8A-8C, andshowing the relatively movable end cap 190 of the balloon catheter 114and handpiece 204. A tubular extension 350 of the end cap 190 shownschematically in FIG. 10A includes a closed distal end 352 and a pair ofside ports 354 just proximal to the distal end. (It should be noted thatthe inflation tube 199 previously shown that connects to the distalballoon 112 is omitted to show the fluid flow control.) The tubularextension 350 fits closely within a bore 356 formed in a proximal end ofthe handpiece 204. Prior to balloon expansion, the components arepositioned as seen in FIG. 10B, with the distal end of the tubularextension 350 positioned within the bore 350 such that the side ports354 are blocked. Distal movement of the end cap 190 as seen in FIG. 10Ccauses the tubular extension 350 to project from within the bore 356into a larger chamber 358, thus exposing the side ports 354 so the fluidmay be injected toward the distal balloon. In this configuration, theend cap 190 must first move distally relative to the handpiece 204, thusadvancing the distal balloon 112, before fluid can be injected toinflate the balloon.

FIG. 11 also shows a portion of the proximal end of an alternativedelivery system 110 similar to the views of FIGS. 9-10, with therelatively movable end cap 190 of the balloon catheter 114 and handpiece204. A tubular extension 360 of the end cap 190 shown exploded in FIG.12A again includes a distal end closed by a plunger 362 and has a pairof side ports 364 just proximal to the distal end. The tubular extension350 fits closely within a bore 366 formed in a proximal end of thehandpiece 204. Prior to balloon expansion, the components are positionedas seen in FIG. 12B, with the plunger 362 sealed against the opening tothe bore 366 such that the side ports 364 are blocked. Distal movementof the end cap 190 as seen in FIG. 12C causes movement of the plunger362 into a larger chamber 368, thus opening the side ports 364 so thefluid may be injected toward the distal balloon. As with FIGS. 10A-10Cabove, the balloon inflation tube 199 that connects to the distalballoon 112 is omitted to show the fluid flow control. Again, thisconfiguration ensures that the end cap 190 must first move distallyrelative to the handpiece 204, thus displacing the balloon 112, beforefluid can be injected to inflate the balloon.

FIG. 13 shows the heart valve delivery system 110 described hereinhaving an alternative safety guard 400 attached on a proximal endthereof. As will be explained, the safety guard 400 prevents prematureinflation of the dilatation balloon 112 of the balloon catheter 114.

FIGS. 14A-14C illustrate the safety guard 400 of FIG. 13 in severaldeployment positions. The safety guard 400 includes a distal hub 402that clips in a fixed position to a proximal end of the handpiece 204 ofthe delivery system 110. The hub 402 is generally cylindrical and has aproximally-extending guide 404 on one circumferential side thereof. Theguide 404 defines an axial channel (not numbered) therein that receivesa proximally-directed finger 406 formed on a catheter push member 408.The catheter push member 408 slides axially relative to the distal hub402 guided by the finger 406 within the channel.

The catheter push member 408 has a catheter engagement piece 410 shapedto conform to the contours of the end cap 190 of the balloon catheter114, as seen in FIG. 13. The catheter engagement piece 410 furtherincludes an inwardly-directed node 412 that fits closely within thelumen of the luer connector 192, as best seen in FIG. 16A, and providesa physical barrier and visual indicator to prevent premature attachmentof a balloon inflation source. It is important to fully advance theballoon catheter 114 prior to inflation of the balloon 112 so as toavoid incorrect expansion of the heart valve, which may causeperformance issues and even force valve removal.

FIGS. 15A-15C illustrate a sequence of operation of the heart valvedelivery system 110 having the safety guard 400, while FIGS. 16A-16Cshow the same sequence in longitudinal cross-section. Initially, thesafety guard 400 and balloon catheter 114 are in a proximal positionwith the finger 406 of the push member 408 received completely withinthe channel formed in the guide 404 of the hub 402 (see FIG. 16A). Inthis position the balloon 112 of the balloon catheter 114 is retractedwithin the heart valve (not shown) to facilitate advancement thereof tothe implantation site. Once the heart valve has been seated at theannulus, the surgeon advances the balloon catheter 114 by, for example,pushing on the proximal facing surfaces of the push member 408.Ultimately, the end cap 190 engages the handpiece 204 of the introducer,as seen in FIGS. 15B and 16B, signifying full advancement of the balloon112 within the heart valve. At this position, the finger 406 of the pushmember 408 emerges from within the channel of the guide 404.

Finally, in FIGS. 15C and 16C, the push member 408 may be detached fromthe fixed hub 402 and discarded. This exposes the luer connector 192such that a complementary connector 414 of a fluid inflation system canbe attached thereto. The push member 408 cannot be removed until it hasbeen advanced in the distal direction along with the balloon catheter114 to disengage the finger 406 from within the channel guide 404. Thisensures that the connector 414 of a fluid inflation system cannot becoupled to the luer connector 192 until the balloon catheter 114 hasbeen fully advanced, thus ensuring that the balloon 112 is properlypositioned within the heart valve prior to inflation.

FIGS. 17A and 17B are perspective views of a still further safety guard500 of the present application having a toggle lever 502, while FIGS.18A-18E show the guard on the proximal end of a heart valve deliverysystem 110 during a sequence of operation. The guard 500 includes aproximal tubular piece 504 having a closed end which fits over andcovers the end cap 190 and luer connector 192 of the balloon catheter114 (see FIG. 18D). As seen in FIGS. 17B and 18B, the tubular piece 502includes an outwardly-directed circular flange 506 in its midsection,and a plurality of shaped and cantilevered fingers 508 distributedcircumferentially around its distal end. The tubular piece 504 fits overthe proximal end of the balloon catheter 114 such that the fingers 508spread apart and snap onto an outwardly-directed rib on the balloondisplacer 198, as seen in the enlargement of FIG. 19A.

The toggle lever 502 pivots in an axial plane about hinge points 510provided on either side of the tubular piece 504, as indicated by themovement arrow in FIG. 18B. The toggle lever extends from flanges 512that pivot at the hinge points 510 to a thumb tab 514. The distancebetween the hinge points 510 and the thumb tab 514 is calibrated suchthat when abutted against the balloon catheter 114, the thumb tab 514provides a barrier to distal movement of the catheter. That is, thethumb tab 514 abuts against the proximal face of the handpiece 204.

FIGS. 19A and 19B are enlarged sectional views through a portion of thesafety guard 500 and heart valve delivery system 110 illustratingrelative engagement and disengagement thereof. More particularly, whenthe balloon catheter 114 is in the retracted position of FIG. 18A, asheld by the toggle lever 502, each of the cantilevered fingers 508engages the outward circular rib on the balloon displacer 198, as seenin FIG. 19A. By pivoting the toggle lever 502 upward, the user mayadvance the balloon catheter 114 distally relative to the handpiece 204,as seen in FIGS. 18B and 18C. The outwardly-directed circular flange 506provides a convenient pushing surface. Eventually, a distal end of theballoon displacer 198 fits within the tubular end of the handpiece 204,which causes the proximal edge of the handpiece to cam an angled surfaceof the cantilevered fingers 508 outward, as seen in FIG. 19B. At thispoint there is nothing preventing the user from pulling the safety guard500 off of the end cap 190, thus exposing the luer connector 192, asseen in FIG. 18D. Ultimately, a mating luer connector 516 at the end ofa fluid delivery tube 518 can be attached to the luer connector 192,thus providing fluid to the balloon catheter 140.

The safety guard 500 thus provides two important safety functions.First, by imposition of the toggle lever 502 between the ballooncatheter 114 and the handpiece 204, the user cannot advance the ballooncatheter relative to the remainder of the delivery system 110. Thus,while the user advances the heart valve on the distal end of thedelivery system 110 to the implantation site, he/she cannotinadvertently advance the dilatation balloon 112 through the heartvalve. Once the heart valve is seated at the annulus, the user flips thetoggle lever 502 outward, thus enabling advancement of the ballooncatheter 114. At the full extent of the balloon catheter travel, thecantilevered fingers 508 are released by engagement with the handpiece204, and the safety guard 500 can be removed, as in FIG. 18D. Thisallows connection of the fluid supply to the luer connector 192. Thus,the user cannot inflate the balloon 112 prior to its full advancementwithin the heart valve.

FIGS. 20-21 illustrate a still further safety guard 600 of the presentapplication showing interaction with the proximal end of a heart valvedelivery system 110 having a balloon catheter 114, as described above.The safety guard 600 includes a stationary part 602 attached to aproximal end of the handpiece 204, and a movable part 604 connected on aproximal end of the balloon catheter 114 and providing a luer connector606. That is, the movable part 604 essentially takes the place of thepreviously-described end cap 190 and luer connector 192, such as shownin FIG. 3, and attaches to the balloon displacer 198.

The stationary part 602 includes a tubular frustoconical sleeve 608 thatengages the proximal end of the handpiece 204 in an interference fit, orit may be adhered thereto. An elongated arm 610 extends proximally andgenerally axially from the sleeve 608 to the proximal end of the movablepart 604. The arm 610 parallels closely the balloon catheter 114, butdiverges away along an offset section 612 adjacent the movable part 604,at least in the retracted position of the catheter as seen in FIG. 20A.At its proximal end, the arm 610 bends back toward the movable part 604and provides a partial tubular luer guard 614 centered along the axis ofthe balloon catheter 114 that receives the luer connector 606. The luerconnector 606 is located on the end of a tubular section 620 having anembossed or printed arrow 622 thereon. Just proximal to the balloondisplacer 198, an enlarged thumb plate 624 having anti-slip groovesfacilitates advancement of the balloon catheter 114 in a one-handedoperation.

FIGS. 21A-21E show several steps in the operation of the safety guard600 during advancement of the balloon catheter 114. Initially, asexplained above, the balloon catheter 114 and movable part 604 of thesafety guard 600 are retracted such that the luer connector 606 resideswithin the luer guard 614. In this configuration, a fluid supply systemcannot be connected to the balloon catheter 114. After preparing theheart valve and delivery system 110, and advancing the heart valve intoposition within the target annulus, the user advances the ballooncatheter 114 by moving the thumb plate 624 in the direction of the arrow622 on the tubular section 620. Once the balloon catheter 114 has beenfully advanced, the luer connector 606 is exposed in the space createdby the offset section 612 of the elongated arm 610, as seen in FIG. 21B.At this point, a mating luer connector 630 on the end of a fluid supplytube 632 can be attached to the luer connector 606 of the ballooncatheter 614. Additionally, the fluid supply tube 632 can be capturedwithin the partial tubular luer guard 614 to help prevent stress at thejunction of the tube and the mating luer connector 630.

Furthermore, various ways can be provided to prevent prematureadvancement of the balloon 114 relative to the handpiece 204. Forexample, a removable safety clip such as the clip 240 described abovewith respect to FIG. 6 can be provided. Alternatively, to eliminateloose parts, the stationary and movable parts 602, 604 can be providedwith cooperating features to prevent their premature relative movement,and to prevent direct axial balloon catheter advancement until thecooperating structures are disengaged.

For instance, the enlarged views of FIGS. 21D and 21E show one versionof cooperating features. More particularly, one side of the thumb plate624 may project outward into interference with a corner 640 of thestationary part 602 at the beginning of the offset section 612. In thisway, distal axial movement of the thumb plate 624, and attached ballooncatheter 114, is prevented. When advancement of the balloon catheter 114is desired, the thumb plate 624 may be displaced laterally a shortdistance, thus freeing it to move distally so as to advance the ballooncatheter 114, as seen by the arrows in FIG. 21E. Other configurationsare possible, such as providing a movable trigger or latch on either thestationary or movable parts 602, 604.

FIGS. 22A-22C illustrate an alternative safety guard 650 similar to thatshown in FIG. 20A but having an angled luer connector 652 on a movablepart 654. As seen in FIG. 22C, the luer connector 652 extends away fromthe axis of the balloon catheter at an angle β, preferably between30-60°, and more preferably about 45°. Additionally, a stationary part656 attached to the handpiece 204 includes a luer guard 658 having anangle that mimics the angle of the luer connector 652. In the retractedposition of FIG. 22A, the luer guard 658 closely receives the luerconnector 652 and prevents attachment of a fluid supply thereto. It isonly after distal displacement of the balloon catheter 114 and theattached movable part 654 can a fluid supply luer connector be attachedto the luer connector 652. Additionally, means for preventing prematureadvancement of the balloon 114 is desirably included, such as aremovable safety clip as in FIG. 6, or cooperating features between themovable part 654 and stationary part 656, such as seen in FIGS. 21D and21E.

In FIGS. 23A-23C, another safety guard 700 of the present application isshown having a semi-tubular stationary part 702 connected to thehandpiece 204 of the heart valve delivery system 110, and a semi-tubularmovable cover 704 that slides axially over the stationary part. As seenin the sectional view of FIG. 23C, the stationary part 702 includes aluer connector 706 on its proximal end. An end cap 708 of the ballooncatheter 114 fluidly connects to the luer connector 706 via a coiledflexible tube 710 positioned in the cylindrical space between thestationary and movable parts 702, 704. In this way, the balloon catheter114 can slide axially relative to the stationary part 702 whileremaining in fluid communication with the proximal luer connector 706.However, in its retracted position shown in FIG. 23A, the movable cover704 extends over the luer connector 706 and prevents attachment of afluid supply thereto. This prevents premature inflation of the balloonof the balloon catheter 114 prior to advancement thereof through theheart valve. The movable cover 704 includes a thumb tab 712 which a usercan press to axially move the cover in a one-handed operation. An innershoulder 714 of the movable cover 704 engages a portion of the ballooncatheter 114 and pushes it distally. As before, a solution forpreventing premature advancement of the balloon 114 is desirablyincluded, such as a removable clip as in FIG. 6, or cooperating featuresbetween the movable cover 704 and stationary part 702 such as in FIGS.22D and 22E.

It should be understood that individual features of the various safetyguards and clips described herein can be interchanged. For instance, asmentioned above, the removable safety clip 240 of FIG. 6 can be suppliedwith the safety guards disclosed in FIGS. 20-23. Likewise, thecooperating features between the movable and stationary parts as shownin FIGS. 22D and 22E can be incorporated into the earlier-describedsafety guards. In short, any conceivable combination of the individualfeatures of the safety clips and safety guards disclosed herein can bemade and should be considered part of the present application.

Various heart valves may be utilized in combination with the deliverysystem components described herein, and any combination not otherwiseexplicitly described is contemplated. Indeed, FIGS. 24A-24C illustratethe delivery system 110 used to deploy a fully expandable heart valve,such as is typically implanted percutaneously. The delivery system 110may be advanced into implant position using a traditional open heartsurgical technique, or with a less-invasive approach, such as through amini-thoracotomy. The surgeon positions the fully expandable heart valvein a correct position and alignment within the annulus and expands itusing a balloon or other expander. Fully expandable prosthetic heartvalves have been developed primarily for use in percutaneous proceduresbecause of the ability to implant the valve without placing the patienton cardiopulmonary bypass. However, the delivery system described hereingreatly reduces the time on bypass, and provides a number of otherbenefits which may be applicable to fully expandable valves. Therefore,it should be understood that the delivery systems herein are not limitedto so-called “hybrid” valves which have a non-collapsible/non-expandableportion and an expandable stent, but also could be used to implant fullyexpandable valves.

FIGS. 24A-24C show the distal end of a heart valve delivery system 110,such as those described herein, delivering an expandable/collapsibleprosthetic heart valve 800 to a treatment site using a valve holder 802.A similar valve holder 802 is shown in U.S. Patent Publication No.2009/0281619, filed Oct. 8, 2008, the disclosure of which is expresslyincorporated herein.

For the purpose of consistency, like elements of the heart valvedelivery system 110 will be given the same numbers as used above. Moreparticularly, the distal end of the delivery system includes a malleableshaft 130 on which is mounted an adapter 208. The adapter 208 receivesin its bore a proximal tubular extension 804 from the valve holder 802.As with the earlier-described engagement between the valve holder 22 andvalve holder adapter 208, as seen in FIG. 5A, the tubular extension 804desirably has a circular groove (not numbered) therein that receives aninwardly projecting bump 218 on the adapter 208. A locking sleeve 206fits closely around the adapter 208 and holds the bump 218 within thegroove, thus locking the valve holder 802 onto the distal end of thedelivery system 110 and enabling quick release thereof.

The valve holder 802 vas a relatively thin distal sleeve portion 806that is desirably formed of Nitinol, stainless steel, or a polymer suchas nylon, PET, PEEK, PE, Pebax, Urethane, and PVC. Prosthetic heartvalve 800 is initially crimped onto the distal end portion of the sleeve806. Desirably, sleeve 806 is formed as a braid or with laser cuts, sothat it can expand radially during implantation of the valve 800 at thetreatment site. If desired, the sleeve 806 can be formed with only aportion of it braided or laser cut where the valve 800 is crimpedthereon, so that the braided portion of the sleeve 806 can be expandedalong with valve 800.

Various expandable heart valves are known in the art, and the presentapplication should not be considered limited to any particular one. Suchvalves typically include a tubular stent frame 810 within which aplurality of flexible leaflets or a xenograft valve (not shown) areattached to provide blood occluding surfaces. The stent frame 810 may besimilar to an expandable Stainless Steel stent used in the SAPIENTranscatheter Heart Valve available from Edwards Lifesciences of theIrvine, Calif.

After the valve 800 is in position for deployment, the surgeon urges theballoon 112 distally relative to malleable shaft 130 and positions itwithin the valve 800, as shown in FIG. 24B. FIG. 24C shows the balloon112 in an expanded state to expand both the sleeve 806 and the valve 800against the annulus. Once valve 800 is expanded to the desired diameter,the balloon 112 can be deflated (not shown) and the delivery system 110retracted from the patient's vasculature. Preferably, sleeve 806 isformed of a resilient material that enables it to spring back inward andbe removed along with the delivery system 110.

While the invention has been described in its preferred embodiments, itis to be understood that the words which have been used are words ofdescription and not of limitation. Therefore, changes may be made withinthe appended claims without departing from the true scope of theinvention.

What is claimed is:
 1. A method of delivery and implant of a prostheticheart valve at a valve annulus, comprising: providing a delivery systemincluding: a handle shaft having a lumen therethrough; and an expansioncatheter extending through the handle shaft having an expandable memberon a distal end, the expansion catheter being capable of linear movementrelative to the handle shaft from a retracted position to an advancedposition, wherein the expansion catheter is a balloon catheter and theexpandable member is a balloon, and the balloon catheter has a proximalluer connector; providing a heart valve including a prosthetic valvehaving an expandable frame, the expandable frame having a contractedstate for delivery to an implant position and an expanded stateconfigured for outward connection to the annulus, the heart valve beingmounted on a distal end of the handle shaft; advancing the distal end ofthe handle shaft so that the heart valve with the expandable frame inits contracted state is located at the implant position adjacent theannulus; ensuring that the expandable member cannot expand until theexpansion catheter is displaced distally to the advanced position bycovering the luer connector with a safety member; displacing theexpansion catheter distally to the advanced position and the expandablemember is located within the expandable frame of the heart valve byremoving the safety member from covering the luer connector; andactuating the expandable member to convert the expandable frame from itscontracted state to its expanded state.
 2. The method of claim 1,wherein the heart valve is fully expandable and mounts onto a flexibletubular valve holder connected to the distal end of the handle shaft,and inflation of the balloon expands the valve holder and the heartvalve mounted thereon.
 3. The method of claim 2, wherein the valveholder has a proximal tubular extension that fits within a tubularadapter at the distal end of the handle shaft, the tubular extension andtubular adapter having interfering components that are locked togetherby assembly of a locking sleeve that fits closely around the tubularadapter enabling quick coupling and release of the heart valve and valveholder from the handle shaft.
 4. The method of claim 2, wherein thevalve holder has a relatively thin distal sleeve portion formed of amaterial selected from the group consisting of: Nitinol, stainlesssteel, polymer, nylon, PET, PEEK, PE, polyether block amide, urethane,and PVC, and the heart valve is crimped onto the sleeve portion fordelivery.
 5. The method of claim 4, wherein the sleeve portion of thevalve holder is formed as a braid or with laser cuts.
 6. The method ofclaim 1, wherein a proximal end of the expansion catheter projectsproximally from out of the handle shaft, and the safety member engagesin a first position between a portion of the expansion catheter thatprojects from the handle shaft and a proximal end of the handle shaft toprevent distal movement of the expansion catheter relative to the handleshaft, and the expandable member cannot expand until the safety memberis displaced from the first position.
 7. The method of claim 6, whereinin the first position the safety member covers the proximal luerconnector on the balloon catheter and ensures that the balloon cannotexpand.
 8. A method of delivery and implant of a prosthetic heart valveat a valve annulus, comprising: providing a delivery system including: ahandle shaft having a lumen therethrough; an expansion catheterextending through the handle shaft having an expandable member on adistal end, wherein the expansion catheter is a balloon catheter and theexpandable member is a balloon, and the balloon catheter has a proximalluer connector; and a safety member arranged in a first position on thehandle shaft so as to prevent pre-mature expansion of the expansionmember, the safety member being displaceable to a second position thatpermits expansion of the expansion member; providing a heart valveincluding a prosthetic valve having an expandable frame, the expandableframe having a contracted state for delivery to an implant position andan expanded state configured for outward connection to the annulus, theheart valve being mounted on a distal end of the handle shaft; advancingthe distal end of the handle shaft so that the heart valve with theexpandable frame in its contracted state is located at the implantposition adjacent the annulus; ensuring that the expandable membercannot expand until the safety member is displaced away from the firstposition by covering the luer connector with the safety member;displacing the safety member away from the first position by removingthe safety member from covering the luer connector; and actuating theexpandable member to convert the expandable frame from its contractedstate to its expanded state.
 9. The method of claim 8, wherein the heartvalve is fully expandable and mounts onto a flexible tubular valveholder connected to the distal end of the handle shaft, and inflation ofthe balloon expands the valve holder and the heart valve mountedthereon.
 10. The method of claim 9, wherein the valve holder has arelatively thin distal sleeve portion formed of a material selected fromthe group consisting of: Nitinol, stainless steel, polymer, nylon, PET,PEEK, PE, polyether block amide, urethane, and PVC, and the heart valveis crimped onto the sleeve portion for delivery.
 11. The method of claim10, wherein the sleeve portion of the valve holder is formed as a braidor with laser cuts.
 12. The method of claim 8, wherein a proximal end ofthe expansion catheter projects proximally from out of the handle shaft,and the safety member engages between a portion of the expansioncatheter that projects from the handle shaft and a proximal end of thehandle shaft.
 13. The method of claim 12, wherein the expansion catheteris capable of linear movement relative to the handle shaft from aretracted position to an advanced position, and when in the firstposition the safety member prevents distal movement of the expansioncatheter relative to the handle shaft.
 14. The method of claim 8,wherein the safety member comprises a locking clip that snaps onto ahandpiece at the proximal end of the handle shaft and onto a proximalend of the expansion catheter, the locking clip preventing expansion ofthe expandable member.
 15. A method of delivery and implant of aprosthetic heart valve at a valve annulus, comprising: providing adelivery system including: a handle shaft having a lumen therethrough;and an expansion catheter extending through the handle shaft having anexpandable member on a distal end, the expansion catheter being capableof linear movement relative to the handle shaft from a retractedposition to an advanced position, wherein the expansion catheter is aballoon catheter and the expandable member is a balloon, and the ballooncatheter has a proximal luer connector; providing a heart valveincluding a prosthetic valve having an expandable frame, the expandableframe having a contracted state for delivery to an implant position andan expanded state configured for outward connection to the annulus, theheart valve being mounted on a distal end of the handle shaft; advancingthe distal end of the handle shaft so that the heart valve with theexpandable frame in its contracted state is located at the implantposition adjacent the annulus; ensuring that the expandable membercannot expand until the expansion catheter is displaced distally to theadvanced position by covering the luer connector with a safety member;displacing the expansion catheter distally to the advanced position andthe expandable member is located within the expandable frame of theheart valve, wherein the step of displacing cannot occur until removalof the safety member from covering the luer connector; and actuating theexpandable member to convert the expandable frame from its contractedstate to its expanded state.
 16. The method of claim 15, wherein aproximal end of the expansion catheter projects proximally from out ofthe handle shaft, and the safety member engages in a first positionbetween a portion of the expansion catheter that projects from thehandle shaft and a proximal end of the handle shaft to prevent distalmovement of the expansion catheter relative to the handle shaft, and theexpandable member cannot expand until the safety member is displacedfrom the first position.
 17. The method of claim 16, wherein in thefirst position the safety member covers the proximal luer connector onthe balloon catheter and ensures that the balloon cannot expand.
 18. Amethod of delivery and implant of a prosthetic heart valve at a valveannulus, comprising: providing a delivery system including: a handleshaft having a lumen therethrough; an expansion catheter extendingthrough the handle shaft having an expandable member on a distal end,wherein the expansion catheter is a balloon catheter and the expandablemember is a balloon; and a safety member arranged in a first position onthe handle shaft so as to prevent pre-mature expansion of the expansionmember, the safety member being displaceable to a second position thatpermits expansion of the expansion member; providing a heart valveincluding a prosthetic valve having an expandable frame, the expandableframe having a contracted state for delivery to an implant position andan expanded state configured for outward connection to the annulus, theheart valve being mounted on a distal end of the handle shaft, whereinthe heart valve is fully expandable and mounts onto a flexible tubularvalve holder connected to the distal end of the handle shaft, andinflation of the balloon expands the valve holder and the heart valvemounted thereon, and wherein the valve holder has a proximal tubularextension that fits within a tubular adapter at the distal end of thehandle shaft, the tubular extension and tubular adapter havinginterfering components that are locked together by assembly of a lockingsleeve that fits closely around the tubular adapter enabling quickcoupling and release of the heart valve and valve holder from the handleshaft; advancing the distal end of the handle shaft so that the heartvalve with the expandable frame in its contracted state is located atthe implant position adjacent the annulus; ensuring that the expandablemember cannot expand until the safety member is displaced away from thefirst position; displacing the safety member away from the firstposition; and actuating the expandable member to convert the expandableframe from its contracted state to its expanded state.
 19. The method ofclaim 18, wherein the valve holder has a relatively thin distal sleeveportion formed of a material selected from the group consisting of:Nitinol, stainless steel, polymer, nylon, PET, PEEK, PE, polyether blockamide, urethane, and PVC, and the heart valve is crimped onto the sleeveportion for delivery.
 20. The method of claim 19, wherein the sleeveportion of the valve holder is formed as a braid or with laser cuts.